1 /* $OpenBSD: ssh-ecdsa.c,v 1.10 2014/02/03 23:28:00 djm Exp $ */
3 * Copyright (c) 2000 Markus Friedl. All rights reserved.
4 * Copyright (c) 2010 Damien Miller. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 #ifdef OPENSSL_HAS_ECC
31 #include <sys/types.h>
33 #include <openssl/bn.h>
34 #include <openssl/ec.h>
35 #include <openssl/ecdsa.h>
36 #include <openssl/evp.h>
48 ssh_ecdsa_sign(const Key *key, u_char **sigp, u_int *lenp,
49 const u_char *data, u_int datalen)
53 u_char digest[SSH_DIGEST_MAX_LENGTH];
57 if (key == NULL || key_type_plain(key->type) != KEY_ECDSA ||
59 error("%s: no ECDSA key", __func__);
63 hash_alg = key_ec_nid_to_hash_alg(key->ecdsa_nid);
64 if ((dlen = ssh_digest_bytes(hash_alg)) == 0) {
65 error("%s: bad hash algorithm %d", __func__, hash_alg);
68 if (ssh_digest_memory(hash_alg, data, datalen,
69 digest, sizeof(digest)) != 0) {
70 error("%s: digest_memory failed", __func__);
74 sig = ECDSA_do_sign(digest, dlen, key->ecdsa);
75 explicit_bzero(digest, sizeof(digest));
78 error("%s: sign failed", __func__);
83 buffer_put_bignum2(&bb, sig->r);
84 buffer_put_bignum2(&bb, sig->s);
88 buffer_put_cstring(&b, key_ssh_name_plain(key));
89 buffer_put_string(&b, buffer_ptr(&bb), buffer_len(&bb));
96 memcpy(*sigp, buffer_ptr(&b), len);
103 ssh_ecdsa_verify(const Key *key, const u_char *signature, u_int signaturelen,
104 const u_char *data, u_int datalen)
108 u_char digest[SSH_DIGEST_MAX_LENGTH], *sigblob;
114 if (key == NULL || key_type_plain(key->type) != KEY_ECDSA ||
115 key->ecdsa == NULL) {
116 error("%s: no ECDSA key", __func__);
120 /* fetch signature */
122 buffer_append(&b, signature, signaturelen);
123 ktype = buffer_get_string(&b, NULL);
124 if (strcmp(key_ssh_name_plain(key), ktype) != 0) {
125 error("%s: cannot handle type %s", __func__, ktype);
131 sigblob = buffer_get_string(&b, &len);
132 rlen = buffer_len(&b);
135 error("%s: remaining bytes in signature %d", __func__, rlen);
140 /* parse signature */
141 if ((sig = ECDSA_SIG_new()) == NULL)
142 fatal("%s: ECDSA_SIG_new failed", __func__);
145 buffer_append(&bb, sigblob, len);
146 buffer_get_bignum2(&bb, sig->r);
147 buffer_get_bignum2(&bb, sig->s);
148 if (buffer_len(&bb) != 0)
149 fatal("%s: remaining bytes in inner sigblob", __func__);
153 explicit_bzero(sigblob, len);
157 hash_alg = key_ec_nid_to_hash_alg(key->ecdsa_nid);
158 if ((dlen = ssh_digest_bytes(hash_alg)) == 0) {
159 error("%s: bad hash algorithm %d", __func__, hash_alg);
162 if (ssh_digest_memory(hash_alg, data, datalen,
163 digest, sizeof(digest)) != 0) {
164 error("%s: digest_memory failed", __func__);
168 ret = ECDSA_do_verify(digest, dlen, sig, key->ecdsa);
169 explicit_bzero(digest, sizeof(digest));
173 debug("%s: signature %s", __func__,
174 ret == 1 ? "correct" : ret == 0 ? "incorrect" : "error");
178 #endif /* OPENSSL_HAS_ECC */